Organic light-emitting diode (OLED) has some features that cannot be achieved by conventional light sources. For example, the OLED has advantages of high quantum efficiency, large area, power-saving, light in weight, slim in volume and flexible property, etc. However, an organic light-emitting layer in an OLED assembly is liable to be deteriorated due to invasion of moisture and oxygen, which may reduce a service life of the OLED assembly. Therefore, package of the organic light-emitting layer is a very important link in manufacturing of the OLED assembly.